Electric igniter for explosive shells.



P. SOHWENKE. ELECTRIC IGNITER FOR EXPLOSIVE SHELLS.

APPLICATION FILED JULY 23, 1908.

Patented Mar.22, 1910.

fire; for: 2 yad/M Milne/a4 e45 UNITED STATES ATENT OFFICE.

rAiT-L s-cnwnnxn, or z'nn-nsr, GERMANY.

ELECTRIC IGNITER FOR EXPLOSIVE SHEDLS.

To all whom it may concern:

Be it known that I, PAUL SOHWENKE, a subject of the German Emperor, and resident of Zerbst, in Anhalt, Germany, have invented certain new and useful Improvements in Electric Igniters for Explosive Shells, of which -the following is a specification.

In many cases it is desirable and even important that explosive shells do burst not only when they hit the mark but also when they touch water and sink therein. 'Such igniters which impart to a shell the abovementioned capability, are already known.

For instance an igniter is known which ef- -fects the ignitlon of the explosive charge by chemicals which upon entrance of water are ignited. Such igniting is howeverunreliable as the chemicals, when the igniter has been stored for-a long time, are through the admission of air and especially by the moisture in the air easily decomposed and thus useless. Further, electric igniters have already become known which act in such a way that water enters a galvanic element, which is filled with dry material, and thereby excites the element whereupon by the electric current produced a platinum wire arranged in the explosi've cartridge is caused to glow. With said known igniters, however, the galvanic battery and the explosive cartridge were separately inserted in the shell. According to the present invention, in such electric igniter the explosive cartridge is to be connected with the galvanic battery to form a homogeneous body which is screwed into the shell. i The accompanying drawing shows central vertical sections through the improved arrangenient.

Figure 1 represents the separated explosive cartridge. Fig. 2 the separated guard inclosing the same, Fig. 3 both the latter parts combined, Fig. 4. the separated galvanic battery, Fig. 5 the separated casing,

Fig. 6 the whole igniter the cartridge being combined with the battery by the casing, and Fig. 7 partof the shell with the improved igniter.

The igniter comprises the electric explosive carriage, the galvanic igniting element, and the casing to be screwed in the shell and which serves to combine the cartridge and galvanic element.

The electric explosive cartridge (Fig. 1) consists of a tube 9 of glass or any other Specification of Letters latent.

suitable material with one closed and one Patented Mar. 22, 19150. Application filed July 23, 1908. Serial No. 445,017.

open end the mouth of said tube being at its edge somewhat bent outward. The tube serves for the reception of priming matter.

Through the walls of the tube two platinum wires p are passed which form the continuation ofthe electric .cirouit. A somewhat thinnerplatinum wire 19 which passes across the interior of the tube connects the two platinum wires p, p by its being soldered thereto and serves with closed electric circuit to glow in order to ignite the priming matter surrounding the same. Said glass tube is similar to the glow-lamps fixed by plaster of paris with its bottom in a glowlamp socket Z with Edison-threads, to which the two platinum wires p,.p are soldered, one terminating in the upper socket edge Z and the other p in the non-conducting foot Z of the socketjust as this is known with glow-lamps. By this arrangement the. electric explosive cartridge can be easily screwed into its' brass ard c (Fig. 2), the foot f of said Edison-t reads a to receive said cartridge. Through a central boring of said foot which for isolation is fitted with vulcanized indiarubber n passes a metal pin 72. which carries a small head 72., said pin effecting the electric connection between the latinum wire p and the carbon pole (Fig. 4) of the galvanic element. The foot f .is provided with two steps 5 b which are both provided with screw-threads. On the step b the guard proper c is screwed over the electric exploslve cartridge, the size of the guard being adapted to that of the cartridge.

At the top 71 the ard is closed but provided with several ho es for the passage of the ploding. The thicker step b of the foot 7? serves with its screw-threads for screwing the cartridge into the casing (Figs. 5 and 6) described below.

The galvanic igniting element (Fig. 4) consists of a zinc pipe 2 which is open at the top and closed at the bottom and serves for the reception of an appropriate quantity of carbon 70 which with its metal-covered pole projects somewhat above the edge of the zinc pipe the latter forming at the same time the zinc electrode. The walls and bottom of said zinc pipe are provided with a number of small holes through which eventually water can enter the interior of the element. The exciting salts necessary ard eing'provided with internal" sparks produced by the cartridge when ex-' I for a vigorous supply of electric current are contained in the carbon,.the latter as well as the interior of the zinc pipe beingin normal condition perfectly dry.

The casing (Fig. comprises a brass pipe 1' andis closed at one end by a strong soldered bottom, the latter being provided with a screw-threaded boring into which the cartridge (shown in Fig. 3) is firmly screwed with its screw-threaded step b. The other open end of the pipe 9" shows at; its outer part a strong thickened screw threaded part "0 to screw therewith the finished igniter into the hollow shell and carries at its'extremity a screw-theaded flange which in its opening receives the metal plate id. The latter closes the open end of the the igniting element.

casing-and carries perforations through which eventually water can enter to excite The inner space of the casing serves for the reception of the igniting element which is so inserted that its carbonpole can be conducted in a metallic way to the insulated olepin h of 'the explosive cartridge WlllCll projects into I /"the space of the casing. To insulate said contact point a thick perforated tightening. washer 'gi lies on the bottom of the casing so as to surround and tighten simultaneously .the insulated pole'pin h 'of the explosive cartridge'as well as the carbon pole pressing against the same under the influenceof a spiral spring m which is provided to. intervene between the bottom ofthe zinc pipe ,2 and the metal plate 11. so that the conv tact between the insulated pole of the explosive' cartridge.pin h ,and the carbon pole of the igniting element cannot lose its intimateiconnection, The spiral spring constituting ametallic conduct between zinc pipe and casing, a closed electric circuit is always] formed between the igniting eleinent and cartridge as the latter is also in fnietallic connection with the casing through their Edison-threads.

"The finished igniter (shown in Fig. 6) is with its screw-threads v screwed into a corresponding screw-threaded opening 0 in the shell preferably in' proximity to the head of not screwed into the shell 5 its intended use. f I. p ,1: Having fully described my invention, what I claim and desire to secure Letters Fatent is 1. An electricignite'r far explosive shells adapted to be operated whentouchingfwa ter, comprising in combination with the shell, an electric explosive cartridge, "a gal} vanic element adapted be excited v the entrance of water, and a casing' containing both the battery and thefi'gniter and lde': signed to be screwed into thejshell, the'ba'ttery, the igniter, and the. casing being so combined as to present always a closed eir-i j cuit, as described. t y

2. An electric igniter for explosive shells adapted to be operated when touching' water, comprising combination with i'the shell, an electric explosive cartridge, *a' gal vanic element designedto be excited by "the 7 entrance of water, a casing designed tobe screwed into saidshell andto connect said cartrldge and elementdand. a ',g1qw 1am socket to eflect the connection.between' said.

cartridge and casing,the whole arrangement being so combined as to present always'a closed electric circuit, all'forfthepurpose set forth.

In testimony whereof I have hereunto set my hand in the presence oftwo subscrib-= L soHwENxn;

ing witnesses.

Witnesses I A. Mt'rILER, P. BROWN. 

